1. Field of the Invention
The present invention relates to the connection of tubular members, more specifically to the connection of pipelines in subsea environments during the laying or repairing of such pipelines. In particular, the invention relates to a locking slip joint useful in pipeline tie-ins.
2. Description of the Prior Art
The laying or repairing of underwater pipelines presents a number of situations requiring tie-ins. It is well known in the art that such tie-ins may be facilitated by the use of slip joints for providing axial translation between end connectors, ball joints, repair welds or the like. It is desirable that such slip joints provide a seal having a structural integrity and reliability at least equal to that of the remainder of the pipeline. It is also desirable that the slip joint provide relative rotation prior to locking to facilitate bolt hole alignment.
Slip joints of the general type under discussion are described in U.S. Pat. No. 3,649,032 to Nelson and in U.S. patent application Ser. No. 738,609 to Martin. The apparatus of the present invention is primarily designed to afford improved reliability and to facilitate remote actuation while maintaining the many advantages of the devices described in the above-mentioned patent and patent application.